大家好,又见面了,我是你们的朋友全栈君。
新版正方教务系统登录界面:
一、需求分析
需要访问教务系统,爬取出课表成绩等信息,并在自己所写的APP上进行展示。由于访问教务系统需要连接校园网,所以本次爬取采用了“内网-教务系统”两级爬取策略,即先模拟登录校园内网,然后携带内网cookies登录教务系统,最终爬取相关信息。
二、模拟登录内网
内网登录界面:
URL:https://webvpn.ncepu.edu.cn/users/sign_in
主要步骤:
-
填好用户名以及登录密码,按下F12,并在Elements中搜索action:
可以看到,我们输入的表单数据最终被提交到了”/users/sign_in”里。 -
点击登录,在Network里面找到sign_in,可以看到我们模拟登录需要的各种信息:
-
开始写代码。
- 第一步主要是获取表单信息以及cookie,可能有的网站这里必须动态请求网页数据来获得form data,具体原因请参考:Exception in thread “main“ org.jsoup.HttpStatusException: HTTP error fetching URL. Status=422, URL=
Connection connection = Jsoup.connect(URL);
connection.header("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.61 Safari/537.36");
Response res = connection.execute(); //获取res.cookies(),后面要用到
Document d = Jsoup.parse(res.body());
List<Element> elements = d.select("form");
Map<String, String> datas = new HashMap<>();
for (Element element : elements.get(0).getAllElements()) {
if (element.attr("name").equals("user[login]")) {
element.attr("value", "************");
}
if (element.attr("name").equals("user[password]")) {
e.attr("value", "******");
}
if (element.attr("name").length() > 0) {
datas.put(e.attr("name"), e.attr("value"));
}
}
USER_AGENT等信息都在这里面:
我们可以打印一下datas:
{user[dymatice_code]=unknown, utf8=?, commit=登录 Login, user[login]=马赛克, user[password]=马赛克, authenticity_token=+BD3FgRXj+LsvgUpS81EKyU7SOF1B6eshSzfo3aMOSHD3LoMsx8ZP85vWNbm1PbPJGbgJqHVbFkTvHuSzDwI8A==}
- 第二步就是提交表单信息以及cookies,进行模拟登录:
Connection connection2 = Jsoup.connect("https://webvpn.ncepu.edu.cn/users/sign_in");
connection2.header(USER_AGENT, USER_AGENT_VALUE);
Response response = connection2.ignoreContentType(true).followRedirects(true).method(Method.POST).data(datas).cookies(res.cookies()).execute();
- 最后一步:打印一下获得的html以及获得的cookies:
System.out.println(response.body());
Map<String, String> map = response.cookies();
for (String s : map.keySet()) {
System.out.println(s + " : " + map.get(s));
}
三、模拟登录教务系统
我们模拟登录进入到了内网界面:
现在我们要模拟登录到新教务系统这个网页,进入到它的登录页面,也就是文章一开始给出的界面:
主要步骤如下:
- 按照模拟登录校园内网的方式,查看需要提交哪些表单数据,这里就不再演示了,直接上代码:
//登录
public boolean beginLogin() throws Exception{
connection = Jsoup.connect(url+ "/jwglxt/xtgl/login_slogin.html").cookies(cookies_innet);
connection.header("Content-Type","application/x-www-form-urlencoded;charset=utf-8");
connection.header("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.61 Safari/537.36");
connection.data("csrftoken",csrftoken);
connection.data("yhm",stuNum);
connection.data("mm",password);
connection.data("mm",password);
connection.cookies(cookies).ignoreContentType(true)
.method(Connection.Method.POST).execute();
response = connection.followRedirects(true).execute();
document = Jsoup.parse(response.body());
//登录成功
//System.out.println(document);
if(document.getElementById("tips") == null){
System.out.println("欢迎登录");
System.out.println(response.cookies());
return true;
}else{
System.out.println(document.getElementById("tips").text());
System.out.println(response.cookies());
return false;
}
}
代码里面的cookies_innet就是模拟登录内网获得的cookies。csrftoken需要额外获取,另外这里面的密码是加密了的,所以我们也需要获取对当前输入密码加密后的密码,代码如下:
// 获取csrftoken和Cookies,并没有出错
private void getCsrftoken(){
try{
connection = Jsoup.connect(url+ "/jwglxt/xtgl/login_slogin.html?language=zh_CN&_t="+new Date().getTime()).cookies(cookies_innet);
connection.header("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.61 Safari/537.36");
response = connection.followRedirects(true).execute();
cookies = response.cookies();
//保存csrftoken
document = Jsoup.parse(response.body());
csrftoken = document.getElementById("csrftoken").val();
}catch (Exception ex){
ex.printStackTrace();
}
}
// 获取公钥并加密密码
public void getRSApublickey() throws Exception{
connection = Jsoup.connect(url+ "/jwglxt/xtgl/login_getPublicKey.html?" +
"time="+ new Date().getTime()).cookies(cookies_innet);
connection.header("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.61 Safari/537.36");
response = connection.cookies(cookies).ignoreContentType(true).followRedirects(true).execute();
JSONObject jsonObject = JSON.parseObject(response.body());
modulus = jsonObject.getString("modulus");
exponent = jsonObject.getString("exponent");
password = RSAEncoder.RSAEncrypt(password, B64.b64tohex(modulus), B64.b64tohex(exponent));
password = B64.hex2b64(password);
}
附加的B64.java与RSAEncoder.java代码:
import static java.lang.Integer.parseInt;
public class B64 {
public static String b64map="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
private static char b64pad = '=';
private static String hexCode = "0123456789abcdef";
// 获取对应16进制字符
public static char int2char(int a){
return hexCode.charAt(a);
}
// Base64转16进制
public static String b64tohex(String s) {
String ret = "";
int k = 0;
int slop = 0;
for(int i = 0; i < s.length(); ++i) {
if(s.charAt(i) == b64pad) break;
int v = b64map.indexOf(s.charAt(i));
if(v < 0) continue;
if(k == 0) {
ret += int2char(v >> 2);
slop = v & 3;
k = 1;
}
else if(k == 1) {
ret += int2char((slop << 2) | (v >> 4));
slop = v & 0xf;
k = 2;
}
else if(k == 2) {
ret += int2char(slop);
ret += int2char(v >> 2);
slop = v & 3;
k = 3;
}
else {
ret += int2char((slop << 2) | (v >> 4));
ret += int2char(v & 0xf);
k = 0;
}
}
if(k == 1)
ret += int2char(slop << 2);
return ret;
}
// 16进制转Base64
public static String hex2b64(String h) {
int i , c;
StringBuilder ret = new StringBuilder();
for(i = 0; i+3 <= h.length(); i+=3) {
c = parseInt(h.substring(i,i+3),16);
ret.append(b64map.charAt(c >> 6));
ret.append(b64map.charAt(c & 63));
}
if(i+1 == h.length()) {
c = parseInt(h.substring(i,i+1),16);
ret.append(b64map.charAt(c << 2));
}
else if(i+2 == h.length()) {
c = parseInt(h.substring(i,i+2),16);
ret.append(b64map.charAt(c >> 2));
ret.append(b64map.charAt((c & 3) << 4));
}
while((ret.length() & 3) > 0) ret.append(b64pad);
return ret.toString();
}
}
import java.math.BigInteger;
import java.util.Random;
public class RSAEncoder {
private static BigInteger n = null;
private static BigInteger e = null;
public static String RSAEncrypt(String pwd, String nStr, String eStr){
n = new BigInteger(nStr,16);
e = new BigInteger(eStr,16);
BigInteger r = RSADoPublic(pkcs1pad2(pwd,(n.bitLength()+7)>>3));
String sp = r.toString(16);
if((sp.length()&1) != 0 )
sp = "0" + sp;
return sp;
}
private static BigInteger RSADoPublic(BigInteger x){
return x.modPow(e, n);
}
private static BigInteger pkcs1pad2(String s, int n){
if(n < s.length() + 11) {
// TODO: fix for utf-8
System.err.println("Message too long for RSAEncoder");
return null;
}
byte[] ba = new byte[n];
int i = s.length()-1;
while(i >= 0 && n > 0) {
int c = s.codePointAt(i--);
if(c < 128) {
// encode using utf-8
ba[--n] = new Byte(String.valueOf(c));
}
else if((c > 127) && (c < 2048)) {
ba[--n] = new Byte(String.valueOf((c & 63) | 128));
ba[--n] = new Byte(String.valueOf((c >> 6) | 192));
} else {
ba[--n] = new Byte(String.valueOf((c & 63) | 128));
ba[--n] = new Byte(String.valueOf(((c >> 6) & 63) | 128));
ba[--n] = new Byte(String.valueOf((c >> 12) | 224));
}
}
ba[--n] = new Byte("0");
byte[] temp = new byte[1];
Random rdm = new Random(47L);
while(n > 2) {
// random non-zero pad
temp[0] = new Byte("0");
while(temp[0] == 0)
rdm.nextBytes(temp);
ba[--n] = temp[0];
}
ba[--n] = 2;
ba[--n] = 0;
return new BigInteger(ba);
}
}
四、爬取成绩和课表信息
终于进入到了教务系统界面,接下来就是爬取成绩和课表信息,然后在自己写的APP中进行展示,效果如下:
不过我们还是得一步步来:
- 获取成绩信息。与前面类似,也需要提交表单数据,过程一模一样,需要提交哪些数据可以参照这篇博文:爬虫时怎么查看需要提交哪些表单数据?
这里直接上代码:
// 获取成绩信息
public void getStudentGrade(int year , int term) throws Exception {
Map<String,String> datas = new HashMap<>();
datas.put("xnm",String.valueOf(year));
datas.put("xqm",String.valueOf(term * term * 3));
datas.put("_search","false");
datas.put("nd",String.valueOf(new Date().getTime()));
datas.put("queryModel.showCount","80");
datas.put("queryModel.currentPage","1");
datas.put("queryModel.sortName","");
datas.put("queryModel.sortOrder","asc");
datas.put("queryModel.sortName","");
datas.put("time","0");
System.out.println(datas);
connection = Jsoup.connect(url+ "/jwglxt/cjcx/cjcx_cxDgXscj.html?gnmkdm=N305005&layout=default&su=" + stuNum);
connection.header("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0");
response = connection.cookies(cookies_innet).cookies(cookies).method(Connection.Method.POST)
.data(datas).ignoreContentType(true).execute();
connection = Jsoup.connect(url+ "/jwglxt/cjcx/cjcx_cxDgXscj.html?doType=query&gnmkdm=N305005");
connection.header("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0");
response = connection.cookies(cookies_innet).cookies(cookies).method(Connection.Method.POST)
.data(datas).ignoreContentType(true).execute();
System.out.println(response.body());
JSONObject jsonObject = JSON.parseObject(response.body());
//System.out.println(jsonObject);
JSONArray gradeTable = JSON.parseArray(jsonObject.getString("items"));
//System.out.println(gradeTable);
for (Iterator iterator = gradeTable.iterator(); iterator.hasNext();) {
JSONObject lesson = (JSONObject) iterator.next();
System.out.println(lesson.getString("kcmc") + " " +
lesson.getString("jsxm") + " " +
lesson.getString("bfzcj") + " " +
lesson.getString("jd") + " " +
lesson.getString("kcxzmc"));
}
}
有一点需要注意:提交参数中的showCount最好大一点,因为我们默认只爬取了第一页的数据,在第一页显示所有成绩信息才能一次性爬取完。
- 成绩信息展示
安卓ExpandableListView的详细使用教程(附代码解析过程)
参考文章
这些文章都是我自己写的,算是对前面零散知识点的一点总结吧:
- JSoup模拟登录网站(以校园内网为例)
- JSoup利用获得的cookies访问该网页中的其它链接
- 爬虫时怎么查看需要提交哪些表单数据?
- JSoup携带cookies连续跳转登录多个界面
- Java爬虫简单判断是否模拟登录成功(以JSoup为例)
- 安卓ExpandableListView的详细使用教程(附代码解析过程)
欢迎大家关注我的微信公众号:KI的算法杂记,有什么问题可以直接发私信。
发布者:全栈程序员-用户IM,转载请注明出处:https://javaforall.cn/150164.html原文链接:https://javaforall.cn
【正版授权,激活自己账号】: Jetbrains全家桶Ide使用,1年售后保障,每天仅需1毛
【官方授权 正版激活】: 官方授权 正版激活 支持Jetbrains家族下所有IDE 使用个人JB账号...